1. Field of the Invention
The present invention relates generally to a foundation pier system, and more specifically to a concentrically loaded pier system with pier cap and lifting assembly subsystems and methods of use thereof.
2. Description of the Related Art
When constructing buildings or other large structures, movement of that structure due to soil movement and compression is a common concern. It is common to offset these issues with piers, piles, and other foundation elements constructed beneath the structure which penetrate deeper into the earth. Typically a borehole is drilled into the ground, and then concrete and reinforcing (e.g. steel rebar) are placed into the bore. These foundation elements help to compensate for poor surface soil conditions and large structural design loads.
Typical existing pier and piles include several variations, each having its own issues. The helical pier suffers from uneven loading and requires that the footing of the structure be compromised. Concrete shoring pads do not penetrate the earth deep enough for many structures and therefore suffer from shifting soil. Concrete pilings suffer a similar fate. Drilled concrete piers are located at a fixed depth at all times, and this depth may be incorrect. Offset steel piers again require that the footing of the structure be compromised when installed, and suffers from uneven loading.
The angle of the shaft on a prior-art drilled concrete pier is not completely vertical, which compromises durability. Drilled concrete piers are drilled to a fixed depth, which very often is not the correct depth. Drilled concrete piers are friction piers meaning they rely on the soil to create friction and press against them to hold them in place. Soil shrinks and expands depending on weather conditions, which will cause them to fail. Drilled concrete piers require a long project time. To start the holes will be drilled, and then the concrete is poured. Next the concrete needs to dry for a week or longer in order to cure and raise the structure. The drilled concrete piers typically require large excavating equipment which is invasive to the homeowner's property.
The prior-art concrete piling pier is made of only concrete and susceptible to cracking and weathering over time. Concrete piling piers are friction piers which rely on the soil to hold them in place. There is a huge design flaw with this system. When the soil gets wet or dry it will expand and contract causing it to lose friction. This means it will eventually fail. This is a common problem with these piers because they rely on the soil which is always changing. The concrete piling pier's shims are not contained, which means that even slight movements in the soil can cause the shims to misalign and cause settlement. The shims on concrete piling piers are often intentionally broken on the job site with a hammer so that they fit correctly. This creates an uneven surface that allows for very little contact between the shim and concrete block, decreasing the strength of the pier.
The prior-art offset steel piers have hollow steel tubing and only use steel in their construction. The offset steel pier is installed on the side of the footing rather than underneath, therefore structural loads do not transfer directly onto the pier. This makes the spot directly under the bracket vulnerable to breaking under pressure. The offset steel pier has a steel bracket with up to a four inch offset which makes them vulnerable to buckling directly beneath the bracket. The majority of foundation repair companies that use the offset steel pier need to use large excavating equipment to install their piers. This requires more money which translates to an increase in their pier pricing. It also increases the chance of damaging a property.
Other prior art systems attempt to improve upon the basic structural pier or pile. These include staged piers having lifting assemblies including jacks mounted directly below the structure. The lifting platform using the jacks can be a problem when the jacks are not properly utilized, resulting in an unstable structure while the pier is being constructed beneath the lifting platform.
What is needed is a foundation pier system including a pier cap subsystem for providing superior stability for the building structure.
Heretofore there has not been available foundation pier system and method of use thereof with the advantages and features of the present invention.